25th Anniversary Essex Otter Survey-From Extinction to Recovery

Surveyor on river bank. Photo: Essex Wildlife Trust

Essex Wildlife Trust are looking for volunteers to help with the 2019-2020 annual Essex Otter survey.    

The survey which runs from October 2019 to June 2020 will mark the 25th Anniversary of the annual county survey, which began in 1996 as a research project by the University of Essex before being incorporated into Riversearch in 2007.

Otters have been part of the fossil record of the British Isles for half a million years but by the 1970s they had declined so much that they were rarely seen at all. By 1986, when the National Otter survey had reached Essex, the Otter was extinct in the county altogether.

Although Otters have been persecuted throughout history, the population crash came as a result of poor water quality. The accumulation of pollutants, namely organochlorines such as PCBs and DDT, and lead in water bodies and ultimately the fish they fed on, interfered with Otter’s reproductive systems, leading to infertility and whole generations dying without offspring to replace them.  

In 1976 concern was so great that Otters were granted legal protection in England and Wales but a turning point only came later with the ban on organochlorines, and the switch to unleaded petrol. Otters began to recolonise neighbouring counties, namely Suffolk, following a reintroduction in 1984, and in 1991 signs of Otters were found on the River Stour and the River Colne.  

By the time of the first Essex Otter survey in 1996 signs of Otters were found in several north Essex Rivers. The survey has since been tracking the Otters as they’ve spread through Essex, catchment by catchment, and in Spring this year an Otter was seen on the Thames at Canvey, the final part of Essex to be colonised.

With Otters now found in every major watercourse in Essex, 2019-2020 will be the last of the annual Essex Otter surveys. Essex Wildlife Trust aims to re-visit all 256 survey points across Essex and South Suffolk, the findings of which will be published in a 25th anniversary report in late 2020. 

Essex Wildlife Trust are looking for both new volunteers, who will be provided with free training, as well as experienced otter surveyors, all of which will be credited in the report and have a copy made available to them.

For more information on how to take part please get in touch with Natalie Singleton, River Catchment Assistant, Essex Wildlife Trust: riverw@essexwt.org.uk or 01621 862974, or visit the Essex Rivers Hub.